<?php
/**
 * Shared state for the server-pass rules.
 *
 * @package A11yMate
 */

namespace A11yMate\Rules\Server;

use A11yMate\Rules\Registry;
use A11yMate\Support\Html;

defined( 'ABSPATH' ) || exit;

/**
 * Holds the parsed page and collects findings.
 */
class Context {

	/**
	 * Document.
	 *
	 * @var \DOMDocument
	 */
	public $doc;

	/**
	 * XPath.
	 *
	 * @var \DOMXPath
	 */
	public $xp;

	/**
	 * Page URL.
	 *
	 * @var string
	 */
	public $url;

	/**
	 * Findings.
	 *
	 * @var array
	 */
	public $findings = array();

	/**
	 * Enabled rule ids as keys.
	 *
	 * @var array
	 */
	private $enabled;

	/**
	 * Per-rule counters.
	 *
	 * @var array
	 */
	private $counts = array();

	/**
	 * Constructor.
	 *
	 * @param \DOMDocument $doc     Document.
	 * @param string       $url     URL.
	 * @param string[]     $enabled Enabled rule ids.
	 */
	public function __construct( \DOMDocument $doc, $url, array $enabled ) {
		$this->doc     = $doc;
		$this->xp      = new \DOMXPath( $doc );
		$this->url     = $url;
		$this->enabled = array_flip( $enabled );
	}

	/**
	 * Is a rule on?
	 *
	 * @param string $rule Rule id.
	 * @return bool
	 */
	public function on( $rule ) {
		return isset( $this->enabled[ $rule ] );
	}

	/**
	 * Query elements, dropping anything in scripts, templates, the admin bar and so on.
	 *
	 * @param string        $expr XPath.
	 * @param \DOMNode|null $ctx  Context node.
	 * @return \DOMElement[]
	 */
	public function q( $expr, $ctx = null ) {
		$res = $ctx ? $this->xp->query( $expr, $ctx ) : $this->xp->query( $expr );
		$out = array();
		if ( ! $res ) {
			return $out;
		}
		foreach ( $res as $node ) {
			if ( $node instanceof \DOMElement && ! Html::in_ignored( $node ) ) {
				$out[] = $node;
			}
		}
		return $out;
	}

	/**
	 * Record a finding.
	 *
	 * @param string      $rule   Rule id.
	 * @param \DOMElement $el     Element.
	 * @param array       $detail Extra detail.
	 * @return void
	 */
	public function add( $rule, \DOMElement $el, array $detail = array() ) {
		if ( ! $this->on( $rule ) ) {
			return;
		}
		$this->counts[ $rule ] = isset( $this->counts[ $rule ] ) ? $this->counts[ $rule ] + 1 : 1;
		if ( $this->counts[ $rule ] > 60 ) {
			return;
		}
		$meta             = Registry::get( $rule );
		$this->findings[] = array(
			'rule'     => $rule,
			'selector' => Html::selector( $el ),
			'snippet'  => Html::snippet( $el ),
			'detail'   => $detail,
			'severity' => $meta ? $meta['severity'] : 'moderate',
		);
	}
}